Safety shear pin assembly



19, 1968 M. M. KINLEY ETAL SAFETY SHEAR PIN ASSEMBLY Filed July 18, 1967 3a a 2 a 0 5 w.

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BY #agJI/u & new! United States Patent 3,411,597 SAFETY SHEAR PIN ASSEMBLY Myron M. Kinley, Chickasha, 0kla., and Clifford E. Anderson, Houston, Tex., assignors to J. C. Kinley Co., a corporation of Texas Filed July 18, 1967, Ser. No. 654,264 8 Claims. (Cl. 175-294) ABSTRACT OF THE DISCLOSURE A safety shear pin assembly for use with any well tool or other device in which a downward force may be imparted thereto, and wherein a shear pin is severed by such downward force with the sheared ends of the pin kept confined within the tool to prevent entry into the well.

Background of the invention The field of this invention is shear pin assemblies for well tools or other devices.

Various types of well tools such as the explosive jar disclosed in United States Patent Nos. 3,199,594 and 3,199,287 employ shear pin connections for maintaining parts in an inoperative relationship until operation or actuation of the tool is desired, at which time a downward jar or other action shears the shear pin connection. Heretofore, at least the sheared ends of the shear pin, and sometimes the central portion thereof, have thereafter been free to fall into the well pipe or casing. The presence of such sheared parts in the Well pipe or casing, although the parts are relatively small, is objectionable because they often interfere with the proper functioning of well tools. For example, in setting a liner in a well casing, the sheared parts may become lodged or wedged in between the liner and the casing and prevent a proper setting of the liner, or otherwise cause a puncturing or damage to the liner or the casing.

Summary of the invention The present invention provides a new and improved safety shear pin assembly wherein a shear pin is disposed in a tool so that upon the severing of the pin, the sheared ends and the central portion of the shear pin are confined within the tool so that such parts do not enter the well pipe or casing, thereby preventing interference with the operation of well tools and other damage.

Brief description of the drawings FIG. 1 is a view, partly in elevation and partly in section, illustrating the safety shear pin assembly of this invention with a perforator well tool, such tool being merely exemplary of various well tools with which the invention may be employed; and

FIG. 2 is an enlarged sectional view, partly in elevation, illustrating the safety shear pin assembly of this invention in detail.

Description of the preferred embodiments In the drawings, the letter S designates generally the safety shear pin assembly of this invention which is adapted to be used in connection with a tool such as the perforator tool T illustrated in the drawings. Although the safety shear pin assembly S of this invention may be used with various types of tools, it is preferably used in conjunction with a wireline W and a wireline actuated jar J of the link type with suitable weights thereabove (not shown). The well tool T with the shear pin assembly S connected therewith is adapted to be lowered into a Well pipe or casing C on the wireline, as will be more fully explained.

As shown in detail in FIG. 2, the safety shear pin as- "ice sembly S includes a first tool member 10 which is in the form of a tube or cylinder in the preferred form of the invention. Such member 10 has a longitudinal recess 10a formed at its upper end which communicates with a bore 10b of a smaller diameter so as to provide a shoulder 10c within the member 10. The first tool member 10- is also provided with one or more lateral openings 10d, the purpose of which will be explained hereinafter. Preferably, a pair of such openings 10d is provided and such openings are in alignment with each other.

A second tool member 12 having a width or diameter corresponding generally to the diameter of the bore 10b is adapted to extend into the recess 10a and downwardly through the bore 10b.

An annular shoulder 12a is formed on the second tool member 12 below the bore 10b for engagement with a corresponding shoulder 10e on the first tool member 10. As will be explained, when the upper portion of the second tool member 12 is supported by a wireline W or other supporting means thereabove, the lower portion of the tool T including the first tool member 10 is suspended from the wireline W through the contact of the co-acting shoulders 12a and Me.

The second 'tool member 12 has a later-ally extending opening 14 through which extends a shear pin 20. In the preferred embodiment of this invention, the lateral opening 14 for the shear pin 20 is oval shaped or elongated so that its lower or bottom surface 14a is disposed below the lower surface 20a of the shear pin 20 and is at all times spaced therefrom so that there is no load imposed upon the shear pin 20 or on retainer pin 30 when the tool is lowered, raised, or otherwise suspended in a well pipe or casing C. The opening 14 is also sufficiently elongated so that its upper surface is in line with or above the upper surfaces of openings 10d when the surfaces 10e and 12a are engaged so as to permit insertion of the shear pin 20 therein, as will be more fully explained.

A shear ring 23 is disposed around the second tool member 12 and is adapted to fit into the longitudinal upper recess 10a of the first tool member 10. Such shear ring 23 has one or more lateral openings 23a which are preferably diametrically aligned with each other and which are adapted to be aligned with the lateral opening 14. Thus, the shear pin 20 extends through the opening 14 and into one or both of the openings 23a. It is to be noted that the diameter or longitudinal width of the opening or openings 23a is substantially the same as the diameter of the shear pin 20 so that there is substantially no longitudinal relative movement between the shear pin 20 and the shear ring 23. It is also to be noted that the thickness of the wall of the shear ring 23 is substantially the same as the annular space between the external surface of the second tool member 12 and the inside surface of the longitudinal recess 10a, the purpose of which will be more evident hereinafter.

Prior to inserting the retaining pin 30, the shear pin 20 is inserted into the opening 14 and either or both of the openings 2.3a by initially aligning all of said openings with one or more of the openings 10d and then pushing the shear pin 20 laterally so that it is in the position shown in FIG. 2, internally of the first tool member 10 and with at least one end thereof in one of the openings 23a, and preferably with both of its ends in opening 23a and with its central portion in the slot or openings 14. After the shear pin 20 has thus been assembled, the tool member 12 is moved downwardly relative to the tool member 10, preferably so as to engage the lower annular surface 23b of the shear ring 23 with the annular shoulder 10c in the first tool member 10. The shear ring 23 is then locked or secured releasably in such position by a retaining pin 30 formed of brass or other similar material which is driven into a. suitable opening in the housing 3 so as to form a tight fit therewith. The ends of the shear pin are thus confined with at least a portion thereof below the lower edges of the lateral openings 10d so that when they are sheared, they cannot fall outwardly through such openings 10d, as Will be more evident hereinafter.

To more fully understand the operation and advantages of the safety shear pin assembly S of this invention, it is illustrated in conjunction with the tool T and the wireline actuated jar .T. Thus, the first tool member 10 may be a part of the body of the tool T, and as illustrated, is the housing for a perforator of any suitable construction, such as the perforator more specifically illustrated in United States Patent No. 3,199,287, and the details of which form no part of this invention. Within the tool member 10, a slidable rod is disposed for engagement with a firing head 36 which is adapted to detonate an explosive 37, as is well known. The explosive 37 is adapted to drive a wedge 38 downwardly for forcing an orifice insert 39 or other similar member laterally into the well casing C. A stop member 40 is disposed below the wedge 38 for stopping the downward travel of the wedge 38 after it has moved downwardly a sufficient distance to force the insert 39 into the casing C. Below the stop 40, any suitable mechanism is provided such as a movable dog 41 which is adapted to be sheared by an upward engagement in a collar C of the casing C so that thereafter the seating dog 42 is pivoted outwardly by a spring 43 to engage within the collar C upon lowering of the tool T. When the tool has thus been seated with the dog 42 in the collar C, the tool may then be actuated for inserting the insert 39, as more fully explained in said Patent No. 3,199,287.

The second tool member 12 may also be a part of the tool T and preferably has a lower head or hammer section 12b which is adapted to engage the upper end of the slidable rod 35 when the shear pin 20 has been severed or sheared. Thus, when the second tool member 12 moves downwardly relative to the first tool member 10 and the pin 20 is severed, the head 12d contacts the rod 35 which transmits its blow to the firing head or pin 36 to detonate the explosive 37 and this in turn causes the wedge 38 to move downwardly to force the orifice insert or other device 39 into the casing C.

For normally suspending the tool T during the lowering thereof into the Well casing C, the second tool member 12 is connected by any suitable means such as the threads 12c and a locking pin 45 to the lower end 46 of a link type jar J or other suitable jarring mechanism. The

link type jar J is of conventional construction and is adapted to be actuated by manipulation of the wireline W thereabove which extends to the surface in the known manner.

During the lowering of the tool T into the well or casing C, the shoulders 12a and 10e are in contact with each other and the lower surface 14a is still spaced from the lower edge 20a of the shear pin 20 so that the weight of the tool T is carried by the wireline W without imposing any load on the shear pin 20. When the tool has reached the elevation for performing the well operation, the wireline W is pulled upwardly to release the retaining dog 41 by engagement in the collar C as is Well understood so as to thereby release the seating dog 42, as previously explained and as is well known. Thereafter, the seating dog 42 is seated in a collar C by the lowering of the tool on the wireline W and when so seated, the wireline W may then be manipulated to obtain a jarring action with the jar J, which action is imparted to the second tool member 12 so that it acts downwardly on the shear pin 20 to shear the pin 20 so as to leave the ends of the pin 20 which are in the lateral openings 23a within such openings 23a while the central portion of the shear pin 20 moves downwardly with the second tool member 12 to a point therebelow. When such shearing of the pin 20 occurs, the head 12b engages the slidable firing rod 35 for actuating the tool T as previously ex plained. It is also to be noted that even though the ends of the pin 20 are sheared, they are still confined by the inner surface of the wall of the recess 10a since their lower edges are disposed below the lower edge of the opening 10d and also their inner surfaces are confined by the external surface of the second tool member 12 which now has moved downwardly below or adjacent to the inner surfaces of the sheared ends of the pin 20. The central portion of the sheared pin 20 is likewise confined within the opening 14 and because of its length, it cannot escape into the well casing C either.

When it is desired to remove the sheared pin 20, the entire tool T is removed from the Well, the retaining pin 30 is knocked out of the hole which it occupies in the first tool member 10, and then the lateral openings 23a and the central opening 14 of the tool member 12 may be aligned with the lateral openings 10d so that the severed sheared pin 20 may be knocked laterally outwardly through one of the openings 10d, using a punch or other similar tool. The shear pin 20 may then be replaced in the same manner as previously explained for the initial assembly, and thereafter the retaining pin 30 may be reinserted so that the safety shear pin assembly S of this invention is again ready for use.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as Well as in the details of the illustrated construction may be made with'm the scope of the appended claims without departing from the spirit of the invention.

We claim:

1. A safety shear pin assembly for a tool, comprising:

(a) a first tool member having a longitudinal rec ss in one end thereof;

(b) a second tool member having one end thereof adapted to extend into said longitudinal recess;

(c) a shear ring surrounding said second tool member and having an external size small enough to enter said longitudinal recess;

(d) said second tool member having a lateral opening for receiving a shear pin;

(e) said shear ring having a lateral opening adapted to be aligned with said lateral opening in said second tool member for receiving an end of a shear pin;

(f) a shear pin in said lateral openings in said shear ring and said second tool member;

(g) said shear pin being severable upon a predetermined longitudinal movement of said second tool member relative to said shear ring; and

(h) the sheared end of the shear pin being confined in said lateral opening in said shear ring to prevent escape thereof from the tool.

2. The structure set forth in claim 1, wherein:

(a) said first tool member has a longitudinal bore communicating with said longitudinal recess; and

(b) said second tool member is also adapted to extend into said longitudinal bore.

3. The structure set forth in claim 1, wherein:

(a) said first tool member has a longitudinal bore communicating with said longitudinal recess;

(b) said second tool member is also adapted to extend into said longitudinal bore;

(c) said lateral opening in said second tool member has a longitudinal distance greater than the width of said shear pin;

(d) co-acting shoulders on said first'and second members for engagement upon a longitudinal movement of said members in one direction and prior to shearing of said shear pin; and

(e) said shear pin being severable upon a longitudinal movement of said first and second members in the other direction.

4. The structure set forth in claim 1, wherein:

(a) said first tool member has a lateral opening through the wall thereof which is adapted to be aligned with the lateral openings in said shear ring and said second tool member for assembling said shear pin therein and inwardly of said lateral opening in said first tool member; and

(b) means for securing said shear ring in said longitudinal recess of said first tool member with said shear pin out of alignment with said lateral opening in said first tool member.

5. The structure set forth in claim 1, wherein:

(a) said shear ring has an additional lateral opening which is also adapted to be aligned with said lateral opening of said second tool member; and

(b) the other end of said shear pin extends into said additional lateral opening of said second tool member whereby both ends of said shear pin are adapted to be severed from the central portion thereof upon a predetermined longitudinal movement of said first and second tool members relative to each other.

6. The structure set forth in claim 1, wherein:

(a) said shear ring has an additional lateral opening which is also adapted to be aligned with said lateral opening of said second tool member;

(b) the other end of said shear pin extends into said additional lateral opening of said second tool member whereby both ends of said shear pin are adapted to be severed from the central portion thereof upon a predetermined longitudinal movement of said first and second tool members relative to each other;

(c) said lateral opening in said second tool member is elongated in cross-section with its longest dimension extending longitudinally and exceeding the width of said shear pin to permit limited longitudinal movement of said second tool member relative to said shear pin without severing the shear pin; and

(d) said lateral openings in said shear ring are of sub- 6 stantially the same width as the width of said shear p11].

7. The structure set forth in claim 1, including:

(a) a well tool connected to said first tool member and positioned therebelow in a well pipe; and

(b) a wireline actuated jar connected to said second tool member and positioned thereabove for elfecting a shearing of said shear pin by actuation of said jar.

8. The structure set forth in claim 1, including:

(a) a well tool connected to said first tool member and positioned therebelow in a well pipe;

(b) a wireline actuated jar connected to said second tool member and positioned thereabove for effecting a shearing of said shear pin by actuation of said J (c) said lateral opening in said second tool member having a longitudinal distance greater than the width of said shear pin; and

(d) co-acting shoulders on said first and second members for engagement upon an upward movement of said second tool member relative to said shear pin and prior to engagement with said shear pin so that said wireline supports said tool in a well through the engagement of said shoulders without imposing a shearing load on said shear pin.

References Cited UNITED STATES PATENTS 2,197,344 4/1940 Matlock 294 2,626,781 1/ 1953 Reynolds 175294 2,819,876 1/1958 Ransom 175294 3,105,549 10/1963 Raulins 166-63 X 3,199,594 8/1965 Kinley 16663 3,255,822 6/1966 Conrad 166-63 X NILE C. BYERS, JR., Primary Examiner. 

